Electric switch.



H. C. ROBINSON.

ELECTRIC SWITCH.

APPLICATION FILEDAAPBl, v1909 Patented Feb. 22, 1910.

2 SHEETS-SHEET 1.'

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..H. G; ROBINSON. ELECTRIC swToH. Y v uPuloA'rlon FILED Mmm, 1 909 A 959,305, Patented Feb.22,1'910.

2 SHEETS-SHEET m56 www* Mm HARRY C. ROBINSON, OF COATESVILLE, PENNSYLVANIA.

ELECTRIC swrrcii.

Specification of Letters Patent.

Patented Fei. v22, 1910.

Application led April 21, 1909. Serial No. 491,206.

To all 'whom it may concern:

Be it known that l, HARRY C. ROBINSON, a

citizen of the United States, residing in Coatesville, Pennsylvania, have invented certain Improvements in Electric Switches, of whichthe following is a specification.

One object of my invention is to provide a switch of the electro-magnetically actuated type which shall possess but relatively few parts and have those of a substantial. construction; the arrangementbeing such that the switch is not likely to get out of order or require any but. a minimum of attention and repairs.

A further object of the invention is to provide an electro-magnetic switch particularly designed for use in motor controlling systems, which shall have its parts so constructed as to permit of its being opened and closed while under load without injury; there being provided a novel form of arc breaking attachment so constructed as to be reliable and eflicient in operation.

lt is also desired to provide a switch havingan arrangement and construction of engaging members particularly designed to 1n-` sure a relatively perfect contactwhen Vthe switch s-closed. p

These objects and other advantageous ends l secure as hereinafter set forth, reference being had to the accompanying drawings, in

which instance are formed as triangular Iprisms' each having a threaded stud projecting through the supporting structure A, whereby it may oe held in position by means of nuts b. In the case of the contact B, the stud is somewhat prolonged for the reception of cable terminals or conducting bars whereby it may be connected in circuit, and in view of connections hereafter described, the stud B is, in the "present instance, i-ust long .enough to properly'recei-ve its retaining nut. A

The two contacts are so mounted that their two contact faces lie in planes at an angle of 900 to'each other, although it is obvious that this angle between the faces may be variedconsiderablywithout departing from my invention.

The movable contact of the switch is illustrated at C and preferably consists of a lamina-ted structure having the form of a truncated wedge. That i. to say, its engaging faces lie in planes bearing the same angularl relation to each other as do the planesI of the engaging faces of the two contacts B and B. The laminationsof this movable contact are so formed and arranged that their ends are capable of respectively engaging the two contacts B and B', and they are clamped together by a nut l threaded on one end of a bar D, passing through them at right angles to their length. Said bar at its opposite end is attached to a cylindrical armature or core CZ opera-tive within a solenoid E, which is provided with a winding of any suitable size. and is preferably inclosed by a protective casing e held to the supporting structure A by bolts e passing through suitable lugs as shown.

F or breaking the are formed when the switch is opened, I provide a blow out magnet F which consists ot a pair of pole pieces j' suitably mounted on the supporting structure A, and connected together'by two bolts f and f2. The first of these bolts f is largeri than the other andlias an elongated threaded extension projecting through the structure A for the reception of a holding nut Z) and any desired number of clamping nuts b. lVound on this stud as a core and electrically connected to it is a current conductor, in thel present instance having the form of a flat copper ribbon f3, whose convolutions are insulated from each other iii any suitable manner, and whose outer end is connected to the main contact B. The magnet thus formed is so arranged that the upper portion ot the main contact B lies within its magnetic field and from Fig. 1 it will be seen that on the top face of said contact there'is removably mounted a carbon block g. This block is held in an undercut recess, and one ot the edges of the contact, as b2, is removable from the body thereof, in order to permit of the block being replaced when burned or Worn.

Mounted upon and electrically connected tothe main Contact B is a lever H', one arm 71, of Whichhas at its lend a cylindrical portion /L so formed thatl its cylindrical face lies parallel to and is capable of engagement 'with the top surface of the carbon block g'. The second arm h2 ofthis lever is connected by a link h3, of liber or other suitable insulating material, with a second lever hpivoted to astud h5 carried by the supporting structure. T his latter lever is provided with an o enino h6 for the assao'e of the armature bolt l), and the various parts are so pro- H is turned on its pivot and the cylindrical i end portion 7L is moved out of engagement with the carbon block g.

The energization of the solenoid E draws the core d into its hollow interior and thereby forces upwardly the laminated movable contact C, so that the inclined ends of this latter' respectively engage and electrically connect the two main contacts'B and B.

Before, thus engage the two main contacts, ver ht is permitted to move upwardly to its fullest extent, under the action of gravhowever, this movable contact can ity-upon the lever larm it and the cylindrical end It', with the result that said end comes into electrical contact with the carbon block g and completes the circuit between the two main contacts. Y

As a consequence, any flashing or arcing which might be produced upon closing the circuit, necessarily' occurs between the carbon block g and the cylindrical end 7L.

lVhen the solenoid E is denergized, the

combined weight of thermovable contact (il, i the armautre bolt D and the co're itself, is f the lesufficient. to cause immediate separation of said movable cont-actI from theA mam contacts B and B, and it will be noted that the break between these contacts is between one-quarter and one-half inch or more before the movable contact engages .the lever it". In t-he meantime, however, the circuit remains closed through main contact B, the lever arm 7L, cylindrical end 7L and carbon block f/ to the main contact B, and .it is finally brolren by the separation of the end 7L from the block g, due to the movement of the lever lr* under the action of the movable contact C and its connected parts. Since, however, the Circuit through the switch includes the winding -f of the blow magnet, -the arc.

finally drawn between the block gV and the end la', is immediately blown out by the action" of the magnetic field existing between the pole pieces f of the blow magnet.

It will be noted that the arms of the lever l i l l i 1 l l tively quick movement of the end of the lever arm t.

By reason of the 'peculiar disposal ofthe inclined fixed contact faces relatively to the inclined and laminated'ends of the movable contactl` l am enabled to secure a very pei'- fect electrical engagement of the .several parteI so that the liabilil, of their heatingl owing to bad contact is reduced to a minimum. I

llf'hile 1l preferably so construct the fixed contacts of my switchcs that their engaging faces lie in plane-gat an angle of about 900 to each other, it is obvious that this single may be materially varied on both sides of a right angle withoutdeparting from my invention, since the end desired, namely the provision of'a wedge-'shaped reces-z for the reception ot' a laminated movable contact ol similar form, is attainedv in. any case.

l claim l. An electric switch, having two fixed main contacts; a movable main contact capable of engagingl said two fixed contacts; an

auxiliary Contact pivoted to one of the fixed main contact-.so as tobe capable of engaging the other;'means operatively connecting the auxiliary contact with the main'movablc contact while leaving said auxiliary c' mart free to move into engagement with tied main contact under the 'action'of gravity; with means for forcibly .maintaining the movable contact in engagement with the fixed contacts.

'2. The combination in a switch of two fixed contacts; a movable main contact capable of connecting/said fixed contacts; an auxiliary contact pivoted on one of the fixed contacts so as to be capable of engaging the other; means for forcibly holding said movable main contact Ain engagement with the fixed contacts;y and means for operatively connecting the auxiliary contactwith .said holding means for the movable :main contact so as tocause said contactsI to move iu opposite directions under operative condi-- mountedon one of the fixed contacts and vcapable of engaging the other fixed contact;

with -nieans controlled by the contact holding means for moving'said auxiliary contact member out of engagement with said other fixed contact after the main movable con-- tact breaks connection with the fixed ramtacts; said auxiliary lcontact member being tree to move under the action of gravity into engagement with its fixed contact when lthe main movable contact moves to engage ythe auxiliary contactmember for causing said two contacts to move in opposite directions.

5. The combination in a switch, of two main fixed contacts; a main movable contact; means for maintaining said movable contact in engagement with the fixed 'confacts; an auxiliary Contact member mount-- ed on one of'the fixed main contacts and capable of engaging the other fixed contact; and means actuated b v the main movable contact for causing it and said lauxiliary contact member to be simultaneously moved in opposite directions aw'ay from one ofthe fixed main contacts after said movable main contact has disengaged the fixed main con- 6. The combination in a switch; of a supporting structure, an electro-magnetic operating means including a bar and means foi1 actuating the same. a movable switch contact carried by said bar, a lever capable of being actuated by said movable elements, two main contacts placed to be electrically connected by said movable contact, an auxiliary contact member mounted on one of` said main contacts and capable of engaging the other, means for connecting said auxiliary contactl member and said lever; and means for extinguishing the arc formed between the auxiliary contact member and the one of said main contacts engaged thereby.

T. The combination in a switch; of two fixed contact members; av carbon contact piece mounted on one of said contacts; an auxiliary contact member mounted on the other contact and capable of engaging the carbon contact. piece; a main movable contact capable of electrically connecting said two fixed contacts; means connecting the main movable contact and the auxiliary con-` tact to cause them to move in oppositedirections away from the fixed contacts, means for extinguishing the arc formed betweenthe auxiliary contact member andthe carboncontact piece; and means for actuating the movable contact member. o

8. rlhe combination of a supporting stiucture; a solenoid mounted thereon; two main fixed contacts carried by the support-ing structure above the solenoid; a movable main contact connected to the core ofl the solenoid and free to fall away from said fixed contacts under the action of' gravity; a lever forming an auxiliary contact and fulciumed on the top of one of the fixed main contacts so as to b e capable of' engaging the other; with means connected to the lever and also to the main movable contact for causing said lever to be turned on its pivot under predetermined conditions. 1

' 9. The combination of a supporting structure; a solenoid mounted thereon; two fixed inain contacts projecting from the structure above the solenoid; a main movable contact.

connected to the core of the solenoid and placed to be free to drop away from said `main contacts under the action of gravity when the solenoid is denergized; a bell crank lever pivot-ed to the top of one. of the fixed contacts; a head carried by one arm of said lever and capable of engaging the second fixed contact; a lever pivoted to Vvthe supporting structure and placed to be acted on by the main contact and its connected parts when the solenoid is denergized; with a link connecting said two levers.

10. An electric switch consisting of two main fixed contacts7 a wedge shaped movable contact, an electro-magnetic device capable of 'forcing the movable contact into engagement with said two fixed contacts, a lever ivoted to one fixed contact and capable o engaging the second fixed contact, and means for operating said lever from the other movable parts of the switch to cause it to break contact with one of the fixed contacts after the movable contact has disengaged said fixed contacts.

In testimony whereof, I have signed my name to this specification, in the presence ot tivo subscribing witnesses.

HARRY C. ROBINSON.

Titnesses WILLIAM E. BRADLEY, WM. A. BARR. 

